Repeater-network-selecting apparatus



c. s. D'EMAREST.

REPEATER NETWORK SELECTING APPRATUS. APPLICATION KFluit) 1uLY9,.1919.

Patented' Feb. 7, w22.

nl; ailier 7b ZI/gwor/` Relays of other Hepeafers IN VEN TOR.

A TT ORNEY UNITED l STATES PATENT OFFICE.

crr'ARLEs s. DEMAREST, or BROOKLYN, NEW YORK, AssreNoR ro AMERICAN TELE- rHoNE AND TELEGRAPH COMPANY, A CORPORATION or NEW YoRx. l

RErEArER-NErWoRK- SELEGTING APPARATUS.

Specification of Letters Patent. Patente-d Feb, 7, 1922.

Application led Julyi9, 1919. Serial No. 309,690.

Toall 'whom t may concern Be it known that I, CHARLESS. DEMAREST, residing at Brooklyn, in the county of Kings and State of New York, have invented cer- .Itain Improvements in Repeater-Network- Selecting Apparatus, of which the following is a specification.

This invention relates to telephone repeaters and. more particularly to means for selecting the proper electrical networks for balancingpa transmission line and its associated apparatus when a telephone repeater is connected thereto.

In order that a telephone repeater may operate properly it is necessary that there i Y tion is to balance the lineand its associated apparatus. The individual networks vthat constitute the balancing group each have an Aimpedance characteristic simulating a part of the transmission circuit, and the entire group, therefore, when combined will have the samecharacteristic las the entire transmissionv line "circuit, including such auxiliary apparatus as may be connected thereto. Such auxiliary apparatus usually con'- sists of composite sets, phantom coils, and composite ringers.' A transmission line may have one or more types of auxiliary apparatus that is, it may be equipped with phantom coils only, or with phantom coils," lom- 'poslte sets and composite ringers, or other combinations. The repeaters that are adapted to be c'onnected'with such transmission lines have associated with them sufficient networks to balance the various types of lines 'with which the repeater may be associated, and also to balance thevarious types of apparatus that may be-associated with the-said lines. It is the purpose of this invention to provide ,'means to control the selection of the proper network for balancing a line and the associated apparatus, and to prevent the connection of a network to the repeater circuit when' its corresponding rpparatus has been disconnected from the me. i' f Further objectsof this invention will appear from Qthe following description of the said invention when read in connection with the attached drawing which is a circuit diagram of one embodiment of the invention.

In the. drawing L1 and L2Hrepresent two physical transmission circuits which conl stitute .the side circuits of thephantom cir-- cuit L3. Each side circuit is eqlipped with a composite set represented by 1 and X2,

whereby these circuits may be used for sivmultaneous telephone and telegraph operation.' Likewise, each side circuit is equipped with a phantom coil, C1 andy C2', by means of which the phantom circuit is superposed upon these side circuits. The two side circuits andthe phantom circuit terminate at the switchboard in jacks J1, J2, and J3, respectively, which are adapted to receive the 'plug P1 of the cord circuit repeater R. Associated with each of the jacks J1, J2, and J 3 is a marginal controlling relay, represented by R1, R2, or R2, which controls the selec-.

tion of the proper type of balancing net-l work. l Associated with the cord circuit'repeater R are various networks. which areI intended to balance the lines and their associated apparatus. The network XR is intended to balance the composite ringing apparatus (not shown), the network CN to balance either of the phantom coilsC1 or (l2 of yao line L1l or line L2, the network CN, to ibalance the effectpof the phantom Vcoils upon the phantom line L31, network CXN to balance the effect of the composite sets on the phantom line L3, the network XN to balance the composite sets associated with either line L1 or L2, since these composite sets are of the same type, and the networks LN and LN3, which are intended to balance the transmission lines L1 or L2 and L3, respectively, exclusive `of the apparatusthat may be associated therewith. Associated with the networks LN and LN 1, are the master controlling 'relaysthRn and R14 respectively whose function isnot only to connect .the line balancing networks LN and LN3 respectively tothe repeater circuit but also to control lthe operation 0f the switching` relays associated with the auxiliary balancing networks by meansxof whlch the said latter networks are connected to thev repeater circuit. A controlling ,keyl K is A associated with the repeater for the purpose of controlling the operation of thel relays by means of which the selection of thel networks is effected. In order to simplify the drawing the. transmission lines in one direc- -xtion and one half of the repeater cord circuit only is shown, since the other half of the said circuit andthe other line circuitsl are similar to thoseshown. Relays R6 and R15 are inthe nature of guard relays to prevent the accidental selection and connection of a balancing network to one repeater circuit which is already connected to a line, yas the result of connecting another repeater to another line. Each repeater-is ydesigned to be used with each line circuit, adapted for repeater operation, and each repeater has individual thereto a plurality ofv networks which may balance any line circuit (and its associated apparatus) with which the repeater may be used. The relaysassociated with the line jacks (owlich R1, R2 and R3 are typical) are common to all of the repeater circuits. The guard relays such as R6 and R15 operate as soon as the final balancing network has been selected'and connected to the repeater connected with any line circuit, and when operated,vthese guard relays prevent other networks from being accidentally connected with the same repeater circuit, when and as the result of connecting another repeater with another line circuit. rlhis will be made clear 1nZ connection with the description of the modeof operating the repeater circuit. v

Let us assume that it -is desired to connect the repeater cord circuit R with the transmission line L1. This is done by inserting the plug R1 in the jack J1, thereby establishing a circuit from battery B1, winding of relay R1, sleeve contacts of plug P1 and jack J1, winding of relay R1 to ground. Relay R4 is operated thereby, but relay R1 being a marginal relay ,does not'receive sutlicient current to cause it to be energized. By inserting the plug of the cord circuit in the jack J1 the operator at the repeater stationis enabled to talk over the transmission line L1 to the operator at. its opposite end. When the repeater operator has received `the req# uisite information regarding the connection that it is desired to have established, she inserts the plug at the other end of the repeater cord circuit in the jack of the desired 'transmission line and then operates the control key K.'v This establishes a circuit from battery R1, contact l of key K conductor 2, windlng of relay R5, Contact 3v of said relay, contact 4 of relay R6, conducresult lof the operation of relays R5, R1, and

R1,I the line.balancinginetwork LN and the phantom vcoilgj:balan'ngnetwork CN are monaci connected to conductors 9 and thereby to the repeater circuit. Furthermore, through the operation of the marginal relay R1 a circuit ise'stablished from battery B3, contact 21 of relay R1, conductor 1l, contact 10 of relay R11, windings of' relays R1, and R10, winding of relay R11 to ground, which operates relays R9, R10, and R11 and connects the composite network XN and the composite ringer network XR to theconductors 9 and thereby to the repeater circuit. As the result of these operations, it will beseen that there has been connected to the repeater circuit the network LN to balance the transmission line`L1, the composite network XN'to balance the composite set X1, the phantom network CN to balance the phantom coil C1, and the composite ringer network XR to balance a composite ringerv connected with line L1, but not shown on the drawing.

Assumefor instance that it is desired to disconnect the composite set X1 from the plugP11 1s inserted in jack-illu.

also apparent that battery R3 associated with a relay R1, is grounded through the winding of relay R12, the resistance ofwhich is sufficiently low to amount to a short-circuit of the windings of the relays R9, R10, and R11 which, as previously stated and. described, 1-

are energized by current from battery L3.

rlhe consequence, therefore, of the short-cinv cuiting-of battery R3, by the disconnection o f the composite set, is to prevent the ope-ration of the relays R1, R10, and R11 that would normally connect the composite balancing network and the compositev ringer balancing network with zthe' re ater circuit. lt will be seen, therefore, tv at theA applicants invention provides a simple method to prevent the connection of balancing networks to the repeater circuit when the .auxiliary apparatus which the said networks are'intended to balance are disconnected from the line circuit.

llhe method of controlling the selection of the proper networks for balancing the 'hantomcircuit is as follows -llf the plug 1- of the cord circuit is inserted in the jack J3 and the repeater control key R has been operated the marginal relay R3 will likewise be operated, and a circuit will be established from battery R1, contact i of key K, con-` lll@ lll@

ductcr 2, thence through the winding and'l@ the contact 13 of relay R14, contact 14 of relay R15, thence over conductor 15 tof ground over the contact of marginal relay R3. Relay R11 is energized thereby and is locked up over a circuit throughconductor 16 and the windings ofrelays R16 and R11 to ground. As a result of the operation of relays R111,

A R16, and R1 the phantom line network LN3 and the network CN3, intended to balance the effect upon the phantom line of the phantom coilsC1 and C2 associated with the side circuits are connected with the repeater circuit over conductors 9. The network CXN, which is intended to balance the eli'ect upon the phantom circuit of the composite sets X1 and X2 associated with the side circuits and Vthe composite ringer network XR, Vwould normally be connected with the repeater circuit by the operation of relays R18,R1, and R11, over a circuit from battery B1, vconductor 17, contact 19 of relay R11, conductor 18, relays R111', R19, and R111 to ground. After the` composite sets have been disconnected' from the side circuits of the phantom, it is, of course, unnecessary and lundesirable to have the phantom c-omposite network connected with the repeater circuit when the repeater cord circuit is connected with the phantom circuit. Consequently, when the ycomposite sets X1 and X2 have been disconv nected from the lines L1 and Lzrespectively,

relays R1, and R13 will be operated thereby,

' which will ground battery B1 associated ,-cuit. n

with the marginal relay R3 of jack J3. In

like manner if the composite ringers have been disconnected from "the side circuits,

battery B4 will be grounded through the contacts of relays R12 and R13, and relays R111, R19', and R11 will be short-circuited.' In consequence thereof the networks CXN and XR are not connected with the repeater cir- In orderto prevent a false. connection of balancing Anetworks to .a repeater circuit after the proper selectionhas been made,

. guard relays, such as Rsvand R111 heretofore referred to, have been provided. When, for exam le, plug P1 was inserted in jack J1 and key 1 had been operated, networks LN, CN, XN, and XR were selected and connected to the repeater ci rcuit. Assuming that no guard relayswere used, i t' another repeater had been connected with line L... by the insertion of its plug in jack J3 and its control key, had been operated, relay R3, associated with the jackA J 1. would be operated which would, momentarily ground co iductor 15 as well as a 'similar conductor' leading vto the other repeater. The grounding of 15 ,would cause relay R14 to operate which would connect networks LN3, CN3, and CXN, to repeater R connected with line L1. Such accidental and false set lection and connection of lthese networks is prevented by. a guard relay such as R15 which operates as soon as contact 22 of relay R11 is closed (or a similar contact of other switching relays) which occursafter the selection has been madeof the final network intended to balance the line and apparatus with which repeater R may be connected, `Each master control relay, such as R5 and R11,has

`its individual guardrelay, as R1, and R11, re-

spectively, and as soon as the final network has been selected all ofthe guard relays will be operated so that no master control relays of the connected repeater circuit will be operated as a result of connecting anotherrepeater circuit to another line circuit.

If a composite set, as for example X1, which is ordinarily associated with line L1, has becomedefective so as to necessitate its removal from the line, and it-is necessary lor desirable to maintain telegraph service over this line, it may be donein the following manner: the defective set X1 may be disconnected in the manner heretofore described by the insertion of plugs R1o and P11 in the jacks J10 and J11, respectively. A portable composite set (not shown) simi- -lar to X1, the conductors of which extending in each direction terminate in a cord and a plug is usually provided as a temporary substitute for the regular composite sets. One of the plugs of this portable set may be inserted' in jack J 1 and the otherplug .in jack J 6, thus connecting the portable composite set between Vthe line L1 and the phantom coil C1'."`When the composite set X1 was disconnected from the line, the battery B3 was grounded over the upper normal lcontact of jack J1, which consequently would prevent, the selection of a composite'. balancing network when the repeater cord" circuit was connected with this'line. ever, when the plug of the temporary oomposite set 1s inserted in the jack Jg, the

How-

ground is removed from battery B3 by the circuits alone',` or to a phantom group com-l prising both physical and phantom '(zircults.-

Although this invention has been shown las embodied in a specific organization, it is apparent that it may be embodied in other and different forms from that shown, with.- out departing from the spirit of the appended claims. 1 li n What is claimed is: 1 1

1. In a telephone transmission system, a combination of a telephone transmission line, auxiliaryapparatus associated with the line, auxiliary appara-tus associated with they lays, a master control relay designed to connect the line network and to control the operation of the switching relays associated with the auxiliary balancing networks whereby the said networks may be connected to the repeater, and a relay directly operable by the connection of the repeater with the transmission line and the actuation of the repeater control key for controlling the energization of the said master control relay.

2. In a telephone transmission system, the combination of a telephone transmission said transmission line, a telephone repeater adapted for connection withthe said transmission line, a repeater control key,- `a network adapted to balance said line, auxiliary networks adapted to balance said auxiliary apparatus, auxiliary network switching relays, a master control relay designed to connect the line network and to control the operation of the switching relays associated with the said auxiliarylbalancing networks whereby the saidy networks may be connected to the repeater, a relay directly operable by the connection of the repeater circuit with the transmission line and the actuation of the repeater control key for controlling the energzation of the said master control relay and means whereby the said auxiliary network switching relays mayv be; short-circuited, thereby preventing the connection of the said networks with the repeater circuit when their corresponding line apparatus 1s disconnected from the line circuit.

y the selection out an auxiliary network for the 3. ln a telphone transmission system, the combination oa group of transmission lines comprising a phantom circuit and two side circuits, auxiliary apparatus associated with each of said side circuits, a telephone repeater adapted for connection with each of said transmission lines, a group of networks adapted to balance saidlines, a second group of networks adapted, to balance said auxiliary apparatus and means for preventing associated with each of. said side circuits, a r

repeater adapted for connection with each of said transmission lines,,a repeater control key, a group of networks adapted to balance said lines.. a second group of networks adapted to balance said auxiliary apparatus, a control relay associated with said phantom circuit and directly operable by .the connection of the'repeater circuit with the transmission line and the actuation of the repeater control key, and switching relays directly energized by said control relay whereby the networks that are adapted to balance the effect upon the phantom circuit of the auxiliary apparatus associated with the side circuits may be connected with the .repeater circuit.

5. In a telephone transmission system, the combination of a group of telephone transmission lines comprising a phantom circuit and two side circuits, composite sets associated with each of said side circuits, a re- -peater adapted for connection with each of said transmission lines, a repeater control key, a group of networks adapted to balance said lines, a second group of networks adapted tobalance said composite sets, a control relay associated with said phantom circuitand directly operable by the connection of the repeater circuit with the transmission line and the actuat1on of the repeater control key, switching relays directly energized by said control relay for connecting with the repeater circuit the auxiliary networks for balancing lthe eii'ect upon the phantom circuit of the auxiliary apparatus associated with said side circuits, and means whereby the said auxiliary network switching relays may be short-circuited, thereby preventing the connection of the said` networks with the repeater circuit.

lln testimony whereof, li have signed my name to this specification this 8th day `of July, 191e.

enteras s. nnuannsr ioo- 

